Hi All, I have noticed that with MST and rapid failover that those ports which are not boundary ports or do not have portfast enabled go through the blocking, listening and learning states again before forwarding.
Here's me shutting off the primary link Gi0/49. You can see the redundant link on Gi0/51 goes straight into forwarding but those ports which are not boundary ports or do not have portfast enabled go through their various states again. Interface Role Sts Cost Prio.Nbr Type ---------------- ---- --- --------- -------- -------------------------------- Gi0/1 Desg BLK 2000000 128.1 P2p Gi0/2 Desg FWD 2000000 128.2 P2p Bound(STP) Gi0/3 Desg FWD 200000 128.3 P2p Bound(STP) Gi0/4 Desg BLK 200000 128.4 P2p Gi0/51 Root FWD 40000 128.51 P2p Interface Role Sts Cost Prio.Nbr Type ---------------- ---- --- --------- -------- -------------------------------- Gi0/1 Desg LRN 2000000 128.1 P2p Gi0/2 Desg FWD 2000000 128.2 P2p Bound(STP) Gi0/3 Desg FWD 200000 128.3 P2p Bound(STP) Gi0/4 Desg LRN 200000 128.4 P2p Gi0/51 Root FWD 40000 128.51 P2p Interface Role Sts Cost Prio.Nbr Type ---------------- ---- --- --------- -------- -------------------------------- Gi0/1 Desg FWD 2000000 128.1 P2p Gi0/2 Desg FWD 2000000 128.2 P2p Bound(STP) Gi0/3 Desg FWD 200000 128.3 P2p Bound(STP) Gi0/4 Desg FWD 200000 128.4 P2p Gi0/51 Root FWD 40000 128.51 P2p When I bring the primary link back up, those same ports go through their blocking, listening and learning states again. Interface Role Sts Cost Prio.Nbr Type ---------------- ---- --- --------- -------- -------------------------------- Gi0/1 Desg BLK 2000000 128.1 P2p Gi0/2 Desg FWD 2000000 128.2 P2p Bound(STP) Gi0/3 Desg FWD 200000 128.3 P2p Bound(STP) Gi0/4 Desg BLK 200000 128.4 P2p Gi0/49 Root FWD 20000 128.49 P2p Gi0/51 Altn BLK 40000 128.51 P2p Interface Role Sts Cost Prio.Nbr Type ---------------- ---- --- --------- -------- -------------------------------- Gi0/1 Desg LRN 2000000 128.1 P2p Gi0/2 Desg FWD 2000000 128.2 P2p Bound(STP) Gi0/3 Desg FWD 200000 128.3 P2p Bound(STP) Gi0/4 Desg LRN 200000 128.4 P2p Gi0/49 Root FWD 20000 128.49 P2p Gi0/51 Altn BLK 40000 128.51 P2p Interface Role Sts Cost Prio.Nbr Type ---------------- ---- --- --------- -------- -------------------------------- Gi0/1 Desg FWD 2000000 128.1 P2p Gi0/2 Desg FWD 2000000 128.2 P2p Bound(STP) Gi0/3 Desg FWD 200000 128.3 P2p Bound(STP) Gi0/4 Desg FWD 200000 128.4 P2p Gi0/49 Root FWD 20000 128.49 P2p Gi0/51 Altn BLK 40000 128.51 P2p I guess what I'll take out of this with MST is that I should enable portfast on those ports where we have devices that can not tolerate a fail over of 20-30secs as the port needs to go through it's spanning tree states whenever a fail over occurs and does the same thing again when the primary link is restored. Cheers. Andy This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. Please notify the sender immediately by email if you have received this email by mistake and delete this email from your system. Please note that any views or opinions presented in this email are solely those of the author and do not necessarily represent those of the organisation. Finally, the recipient should check this email and any attachments for the presence of viruses. The organisation accepts no liability for any damage caused by any virus transmitted by this email. _______________________________________________ cisco-nsp mailing list cisco-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/